8223188: Removed unnecessary #ifdef __cplusplus from .cpp sources

Reviewed-by: herrick, almatvee, iklam

Author: Alexey Semenyuk

src/jdk.jpackage/windows/native/libjpackage/WindowsRegistry.cpp

@@ -68,9 +68,9 @@ std::wstring GetLongPath(const std::wstring& path) {
 
 } // namespace
 
-#ifdef __cplusplus
+
 extern "C" {
-#endif
+
 #undef jdk_jpackage_internal_WindowsRegistry_HKEY_LOCAL_MACHINE
 #define jdk_jpackage_internal_WindowsRegistry_HKEY_LOCAL_MACHINE 1L
 
@@ -216,6 +216,4 @@ extern "C" {
          return JNI_FALSE;
      }
 
-#ifdef __cplusplus
-}
-#endif
+} // extern "C"

src/jdk.jpackage/windows/native/libjpackage/jpackage.cpp

@@ -30,9 +30,7 @@
 #include "JniUtils.h"
 #include "MsiDb.h"
 
-#ifdef __cplusplus
 extern "C" {
-#endif
 
     /*
      * Class:     jdk_jpackage_internal_ExecutableRebrander
@@ -159,6 +157,4 @@ extern "C" {
         return 1;
     }
 
-#ifdef __cplusplus
-}
-#endif
+} // extern "C"